(1) Field of the Invention
The present invention relates generally to a fuel supply control system for an internal combustion engine of an automotive vehicle, and, more specifically, to a fuel supply control system which controls the air and fuel mixture for the engine according to various engine operating conditions obtained from various sensed information in order to reduce pollution from the exhaust gas.
(2) Description of the Prior Art
In a fuel supply control system of an internal combustion engine of an automotive vehicle (e.g., electronic fuel injection control system, electronic carburetor, etc.), there may be provided a fuel cutoff function during deceleration in order to improve exhaust gas purification and reduce fuel consumption and prevent a catalytic converter in the exhaust manifold of the engine from burning out.
The fuel cutoff is carried out during deceleration of the automotive vehicle depending upon whether particular engine operating conditions are satisfied; e.g., whether the throttle valve in the intake manifold is in the idling position, the engine rotational speed is above a predetermined value, and the cooling water temperature is above a predetermined value. Although in the above-described control system the fuel supply is cut off and restored depending upon the operating conditions of the automotive vehicle, when the fuel supply is cut off or restored this causes a change in the driving torque for the vehicle. Consequently, the vehicle occupants are often subjected to undesirable jolting, particularly, in low gear where the driving torque is relatively large so that the change in the torque produces a sizeable jolt.